qpms/kahansum.h

   1 #ifndef KAHANSUM_H
   2 #define KAHANSUM_H
   3
   4 #include <complex.h>
   5
   6 static inline void kahaninit(double * const sum, double * const compensation) {
   7         *sum = 0;
   8         *compensation = 0;
   9 }
  10
  11 static inline void kahanadd(double *sum, double *compensation, double input) {
  12         double compensated_input = input - *compensation;
  13         double nsum = *sum + compensated_input;
  14         *compensation = (nsum - *sum) - compensated_input;
  15         *sum = nsum;
  16 }
  17
  18
  19 static inline void ckahaninit(complex double * const sum, complex double * const compensation) {
  20         *sum = 0;
  21         *compensation = 0;
  22 }
  23
  24 static inline void ckahanadd(complex double *sum, complex double *compensation, complex double input) {
  25         complex double compensated_input = input - *compensation;
  26         complex double nsum = *sum + compensated_input;
  27         *compensation = (nsum - *sum) - compensated_input;
  28         *sum = nsum;
  29 }
  30
  31 #endif //KAHANSUM_H